Technical Field
The present invention relates to a sheet aligning apparatus, an image forming system, and a sheet post-processing apparatus, and in particular, relates to a sheet aligning apparatus that aligns sheets conveyed to a sheet stack portion while pushing the sheet in a direction perpendicular to a sheet conveying direction, an image forming system including an image forming portion that forms an image on a sheet and the sheet aligning apparatus, and a sheet post-processing apparatus including the sheet aligning apparatus and a post-processing portion that performs a post-process on a sheet or a sheet bundle.
Description of the Related Art
Conventionally, in the field of image forming systems, there have been widely known sheet aligning apparatuses for aligning image-formed sheets and forming sheet bundles as preprocessing for performing post-processes such as stapling processes or as preference of operators. In general, such a sheet aligning apparatus includes a sheet stack portion on which sheets are stacked, an aligning member that aligns sheets conveyed to the sheet stack portion by pushing the sheets in a direction perpendicular to a sheet conveying direction, and a moving device that moves the aligning member between an aligning position and a non-aligning position.
A processing tray or the like other than a stack tray on which sheets (sheet bundles) are discharged accordingly is often adopted as the sheet stack portion. Further, an aligning plate that aligns sheets stacked on the sheet stack portion by pushing the sheets in a width direction is often adopted as the aligning member. Such an aligning member is configured to be movable between an aligning position and a non-aligning position with a moving device that includes a drive source such as a motor, and a drive force transmitting portion such as a gear, a pulley, and a belt.
Examples of a sheet aligning apparatus described above include a sheet post-processing apparatus in which aligning control is varied in accordance with the number of sheets conveyed to the sheet stack portion (processing tray) as disclosed in Japanese Patent No. 4880575 and a sheet post-processing apparatus in which an aligning process is varied under conditions of sheet basis weight (sheet weight (grams) per square meter) and sheet size difference as disclosed in Japanese Patent No. 5288377.